You're going to need to get some info from the seller. Ask them to measure center-to-center on the bolt holes to get the length (just in case they measured the tire thing, which is wrong). Whats the length of the one on your bike? What's the travel of this shock and does it match what you have now?
It's a good shock and if it does fit you'll most likely be happy with it. If it doesn't fit, you won't be so happy.